{"id":10321,"date":"2026-07-03T17:39:42","date_gmt":"2026-07-03T17:39:42","guid":{"rendered":"https:\/\/kapdec.com\/help\/?p=10321"},"modified":"2026-07-03T17:39:42","modified_gmt":"2026-07-03T17:39:42","slug":"environmental-impacts-on-enzyme-function","status":"publish","type":"post","link":"https:\/\/kapdec.com\/help\/environmental-impacts-on-enzyme-function\/","title":{"rendered":"Environmental Impacts On Enzyme Function"},"content":{"rendered":"
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KAPDEC® | Elite STEM Learning Platform | https:\/\/kapdec.com<\/a><\/p>\n

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Unit: Cellular energetics<\/strong><\/h2>\n

Chapter: Environmental impacts on enzyme function<\/strong><\/h3>\n

Reference:<\/em><\/strong> Temperature, Hydrogen -ion concentration, Concentration of the enzymes, Concentration of the substrate, Concentration of the end products, Hydration <\/strong><\/em><\/p>\n

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Learning objectives<\/strong><\/p>\n

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  • To understand the effect of environment on enzymes<\/li>\n<\/ul>\n

    The presence of enzymes not only accelerates or retards the chemical reactions but due to their high specificity they are able to regulate several chemical reactions taking place in a cell simultaneously. In other words, enzyme specificity causes an independent control of each reaction.<\/p>\n

    Each enzymatic reaction, like all reactions is again governed by a few factors and the influence of all these factors upon enzymatic reactions.<\/p>\n

    Temperature-<\/strong>it is one of the most important factors which control effectively the rate of enzymatic reactions.<\/p>\n

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    • At 0 degree C, the rate of an enzyme-catalysed reaction is practically zero<\/li>\n
    • The enzymatic reactions rise with the rise in temperature up to 40 degrees<\/li>\n
    • The increased temperature has got either a direct effect on the reaction system or it may have some effect on the structure of the enzyme.<\/li>\n
    • The optimum temperature for an enzymatic reaction lies between 30-40 degrees<\/li>\n
    • Activity or the rate of reaction decreases at higher temperature which favours the partial inactivation of the enzymes. The enzymes are destroyed due to protein denaturation<\/li>\n<\/ul>\n

      Hydrogen -ion concentration<\/strong>– the enzymes are very restricted in their activity by the hydrogen-ion concentration of the medium in which they are acting<\/p>\n

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      • The optimum Ph value for the enzymatic activity varies considerably<\/li>\n
      • The pH 7.5 is found to be optimum for the conversion of malic acid to fumaric acid, but for the reverse reaction the optimum pH is about 6.2<\/li>\n
      • The general range of pH values for the enzymatic activity varies from pH 1.5-10.0<\/li>\n
      • At higher or lower pH values the enzymes are inactivated, first reversibly and then irreversibly, causing an ultimate decrease in the activity.<\/li>\n
      • Changes in the pH cause denaturation of the enzyme molecule resulting in the decrease of enzymatic activity<\/li>\n<\/ul>\n

        Concentration of the enzymes<\/strong><\/p>\n

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        • If there is an excess substrate available and the pH, temperature and other conditions are not limiting, then there is a linear relationship between the concentration of the enzymes and the rate of enzymatic reactions i.e., by doubling the number of enzymes the activity can also be increased.<\/li>\n
        • Increasing the enzyme concentration, in fact, increase the number of available active sites, thus increasing the chance of reactive contact between enzyme and substrate<\/li>\n<\/ul>\n

          Concentration of the substrate<\/strong><\/p>\n

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          • Increase in the substrate concentration causes an increase in the number of reacting molecules in the vicinity of the enzyme’s active sites which therefore increase the rate of an enzyme catalysed reaction<\/li>\n
          • The increase in substrate molecules in the reaction, causes an active accumulation of end products, which until and unless are removed cannot accelerate the reaction rate<\/li>\n<\/ul>\n

            Concentration of the end products<\/strong><\/p>\n

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            • Like all chemical reactions, the enzymatic reactions also follow the laws of chemical equilibrium, which means that the active accumulation of the end products will cause a decrease in the reaction rate.<\/li>\n
            • The velocity of the enzymatic reactions, therefore, depends on the speed with which the products are removed from the medium.<\/li>\n<\/ul>\n

              Hydration <\/strong><\/p>\n

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              • The amount of water in the medium may have a direct effect on the enzymatic activity<\/li>\n
              • During germination, the activity of the enzymes increases due to increase in the hydration of the tissues<\/li>\n<\/ul>\n

                Solved examples<\/strong><\/p>\n

                Example 1<\/strong>. At high temperatures, the rate of enzyme action decreases because the increased heat……<\/p>\n

                a) neutralizes the acids and bases in the system<\/p>\n

                b) alters the shape of the active site of the enzyme<\/p>\n

                c) increases the concentration of the enzyme<\/p>\n

                d) changes the pH of the system<\/p>\n

                Solution 1:  <\/strong>b. At high temperatures, the rate of enzyme action decreases because the increased heat alters the shape of the active site of the enzyme<\/p>\n

                Example 2<\/strong>. How does an increase in substrate affect reaction rate?<\/p>\n

                a) Decrease forever b) Increase forever<\/p>\n

                c) Decrease until enzyme saturated d) Increase until enzyme saturated<\/p>\n

                Solution 2: <\/strong>Increase in substrate increases the reaction rate until enzyme is saturated.<\/p>\n

                                                              Summary<\/strong><\/p>\n

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                • Enzyme specificity causes an independent control of each reaction<\/li>\n
                • The optimum temperature for an enzymatic reaction lies between 30-40 degrees<\/li>\n
                • The general range of pH values for the enzymatic activity varies from pH 1.5-10.0<\/li>\n
                • Increasing the enzyme concentration, in fact, increases the number of available active sites<\/li>\n
                • Increase in the substrate concentration causes an increase in the number of reacting molecules in the vicinity of the enzyme’s active sites which therefore increase the rate of an enzyme catalysed reaction<\/li>\n
                • The active accumulation of the end products will cause a decrease in the reaction rate.<\/li>\n
                • The amount of water in the medium may have a direct effect on the enzymatic activity<\/li>\n<\/ul>\n

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